This invention relates to certain novel curing systems for copolymers of ethylene with carbon monoxide as well as to curable compositions comprising such copolymers together with a curing system of the type disclosed hereafter and to cured polymers obtained by heating the above curable compositions to their cure temperature.
Dipolymers of carbon monoxide with ethylene and terpolymers with ethylene and another ethylenically unsaturated monomer such as, for example, methyl acrylate, or vinyl acetate are well known. Such copolymers are known to contain 1,4-diketo functions arising from CO/unsaturated monomer/CO triads. Although such polymers can be cured by known free radical techniques, for example, in the presence of peroxides, free radical curing suffers from various shortcomings. Thus, for example, because of the inherently non-discriminating nature of peroxide cures, various customary additives, which could be adversely affected by the peroxide (for example, certain fillers, and plasticizers), cannot be used. Furthermore, peroxides have a deleterious effect on commonly used antioxidants and processing oils.
It is, therefore, desirable to have available a non-peroxide curing system for ethylene/carbon monoxide copolymers.